Rotary compressor for gas or liquids with rotor eccentrically mounted in cylindrical housing



March 31, 1953 K. VOZNICA 2,533,292

ROTARY COMPRESSOR FOR GAS 0R LIQUIDS WITH ROTOR ECCENTRICALLY MOUNTED IN CYLINDRICAL HOUSING Filed Feb. 18, 1949 2 SHEETS-SHEET l JNVENTOR. Kfl RE L, v0 ZN (c4 March 31, 1953 K. VOZNICA ROTARY COMPR 0 FOR GAS OR LIQUI ECCENTRICA NTED IN CYLINDR Filed Feb. 18, 1949 2,633,292 WITH ROTOR L HOUSING 2 SHEETS-SHEET 2 INVENTOR. KAREL V Z VICA BY 117-7 mvsy Patented Mar. 31, 1953 ROTARY COMPRESS UIDS on FOR GAS on LIQ- WITH ROTOR EOCENTRIGALLY MOUNTED IN CYLINDRICAL HOUSING Karel Voznica, Brunn, Czechoslovakia ApplicationFebruary 18, 1949, Serial No. 77,086 In Czechoslovakia February 21, 1948 4 Claims. (01. 230-452) The object of the invention is a rotary compressor with a rotor eccentrically mounted in the cylinder housing and having sealing blades slidable in radial slits, these blades being pressed by centrifugal force on to the interior cylindrical surface of the cylinder during operation of the compressor.

'The drawback of the known compressors of this kind consisted in insufficient sealing on the faces of the cylinder housing, considerable leaking being observed at these points resulting from warming up of the compressor and wear of the blades so that such a compressor could not be used for high pressures.

The invention aims to remove this drawback and consists in that there are provided sealing blades consisting of alternately arranged compact blades and divided half-blades separated by a wedge-shaped gap, these latter being pressed on the cylinder covers by the pressure of oil. The hydrostatic oil pressure produced by the centrifugal force during rotation of the rotor exerts an adequate force so that there is no unduly high friction on the surfaces of contact between the blades and the cylinder covers.

The efliciency of seal attained on the inner faces of the housing of the compressor makes it furthermore possible to use an improved system of distribution of the compressed medium which system consists in that a pair of longitudinal ducts are arranged in the rotor adjacent each blade, said ducts communicating one towards the suction cover and the other towards the delivery cover of the compressor while arcuate distribution ducts are arranged coaxially with the rotor in the cylinder covers. The distribution is attained by alignment of the lateral mouth of the rotor duets with the corresponding arcuate ducts in the cylinder covers, thus making it possible to use, for filling or delivery, a larger portion of the rotor revolution than it was possible up to now and thus to improve the filling and emptying of the working space.

The object of the invention is illustrated by way of example on the attached drawing in which:

Fig. 1 is an axial longitudinal section of the compressor,

Fig. 2 a cross section taken on line IIII of Fig. l, with illustration of the distribution at the suction end, and

Fig. 3 is a section taken on line IIIIII of Fig. 1, with illustration of the distribution at the delivery end of the cylinder.

On the base I is mounted the compressor body 2 comprising a vertical plate 2 fastened to the base by screws, and a casing 3. The vertical plate is connected to the casing by screws.

The vertical plate 2 and the casing 3 are penetrated centrally by a shaft 4 on which a rotor 5 is mounted. Eccentrically to the latter is situated a ring 6 forming the working cylinder the interior of which serves as a sliding surface for two groups of blades 11 and I1 which are not connected to each other and are radially slidable in radial slits 1 of the rotor 5.

To the faces of the rotor adhere the covers 8, 9 of the cylinder space which are connected with the vertical plate by screws 25, passing through circular holes of the ring 6.

In each of the front covers 8, 9 is situated centrally to the rotor one arc-shaped groove l0, H of which the groove in is, by means of a duct l2 passing through the cover 8 and the vertical plate 2, with a fitting I 3 to which the suction tube of the compressor is connected while the second groove H by a duct l4 communicates with the space I5 between the cover 9 and casing 3, which space is the delivery space of the compressor and to which the delivery tube I6 is connected.

The loose blades ll, slidable in radial slits 1 and touching the covers 8 and 9, have the length of the cylinder and are exposed, each independently from the other blades of the same group, to centrifugal force when the rotor revolves. Between each two compact blades I! are inserted two parted half-blades l7 enclosing between them a wedge-shaped gap I1. During rotation of the rotor the gap is filled and the hydrostatic pressure produced by centrifugal force presses the blade halves ll towards the covers 8 and 9. The lubricating oil is supplied from the oil reservoir Which is formed by the delivery space l5 and which is filled by means of a lubricating pump.

Therefore the seal obtained by these blades is perfect even at high pressures.

The delivery space I5 is filled with oil to a certain level, the oil screen is preventing the oil from entering the delivery tube H5. The packing gland l9 prevents the escape of oil at the shaft endl and also the sucking of false air as well as escape of the medium at this point.

Four ducts 20, 20', 2|, 2| situated near the blades IT, IT and provided in the rotor 5 cooperate with the arcuate grooves I0, I l in the front covers 8, 9. Pairs of these ducts 20, 20' and 2|, 2| are opposed to each other; the ducts 20, 20' cooperate with the arcuate groove l0 communicating with the suction tube and the ducts 2|, 2 l cooperate with the arcuate groove 1 1 communicating with the delivery space.

In Fig. 2 is illustrated in dotted lines the arouate groove ill in the cover 8 and distribution of the medium at the suction end takes place when the mouth of the duct 20 or 20' aligns with the groove which is long enough to keep up the communication with the suction tube for the whole time of revolution of the rotor during which the space 22 increases its volume. The communication with the delivery groove H (dotted in Fig. 3) is realized when the mouth of the delivery duct 2! or 21 aligns with the groove and the length of this groove is selected so as to establish this communication at a moment when the pressure in the diminishing crescent-shaped working space reaches the working pressure of the compressor, and to keep it up for the whole time of diminution of the working space. Thus ideal filling and perfect emptying of the working space is obtained with small dead space and thereby also good efiiciency of the compressor.

The shaft 4 is formed with a longitudinally extending bore 21 which communicates at one end thereof with the pressurized chamber 15. A plurality of radially extending passages 28 are formed in the shaftv 4 and communicate at their opposite ends with the slits l and the bore 21. The lubricating passages 29 extend from the bore 27 for lubricating the shaft bearings. In operation, the fluid under pressure will pass through the bore 21 and passages 28 into the slits l and will fill the wedge-shaped space il'" between the lades H. The blades ll" will then be urged against the covers 8 and 9 for sealing the blades relative to the covers 8 and 9, The fluid passing into the slits 7 will also serve to lubricate the blades and decrease the wear thereof.

What I claim is:

l. A rotary compressor comprising a rotary cylinder eccentrically mounted in a cylindrical housing, said cylindrical housing being closed by fiat covers at each end, an outer casing enclosing the cylindrical housing and defining a pressure fluid containing space between said casing and said housing, radial slits formed in said rotary cylinder and opening at the opposite ends of the latter, sealing blade assemblies radially slidable in said slits and composed by alternately arranged one piece blades and pairs of axially separable blade halves, each pair of blade halves defining a gap between their confronting edges, a central bore in said cyzinder communicating at one end with said pressure rluid containing space, and radial ducts in the rotary cylinder connecting said central bore with the bottom of each of said radial slits so that fluid under pressure may pass from said pressure fluid containing space into said gaps to move the related blade halves axially into sealing engagement with said flat covers.

2. A rotary compressor comprising a rotary cylinder eccentrically mounted in a cylindrical housing, said cylindrical housing being closed at one end by a suction cover and at the other end by a delivery cover, an outer casing enclosing said cylindrical housing and defining a pressure fluid containing space between said outer casing and said housing, radial slits formed in said rotary cylinder and opening at the opposite ends of the latter, sealing blade assemblies radially slidable in said radial slits and composed by alternately arranged one piece blades and pairs of axially separable blade halves, each pair of blade halves defining a gap between their confronting edges, a central bore in said rotary cylinder communicating at one end with said pressure fluid containing space, radial ducts in the rotary cylinder connecting said central bore with the bottom of each of said radial slits so that fluid under pressure may pass from said pressure fluid containing space into said gaps to move the related blade halves axially into sealing engagement with said flat covers, a pair of longitudinal ducts provided in said rotary cylinder in proximity of each of said blade assemblies, said longitudinal ducts opening radially outward at the periphery of said rotary cylinder and alternately at the ends of the latter facing said suction and delivery covers, arcuate grooves formed in said suction and delivery covers concentrically with the axis of rotation of said rotary cylinder to establish the inlet and outlet, respectively, of the fluid being compressed.

3. A rotary compressor according to claim 2, wherein said confronting edges of said pairs of blade halves diverge in the direction toward the axis of rotation of said rotary cylinder so that said gaps are substantially V-shaped.

l. A rotary compressor according to claim 2, including an outlet duct extending from said arcuate groove formed in said delivery cover and opening into said pressure fluid containing space, an outlet port formed in said outer casing for communication with a point of use, and an oil separator situated in said casing before said outlet port.

KAREL VOZNICA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 741,617 Bogart Oct. 20, 1903 968,859 Kruger Aug. 30, 1910 1,280,306 Rolaff Oct. 1, 1918 1,358,176 Rolafi Nov. 9, 1920 1,619,429 Maillefer Mar. 1, 1927 1,865,666 Aruga July 5, 1932 1,977,780 Stageberg Oct. 23, 1934 2,004,958 Mitchell June 18, 1935 2,068,803 Johnson Jan. 26, 1937 2,233,082 Kucher Feb. 26, 1941 FOREIGN PATENTS Number Country Date 58,544 Norway 1937 285,636 Italy May 18, 1931 543,037 France Aug. 25, 1922 778,346 France Dec. 22, 193 1 

